fix(user-center): use the reference trend sprite for experience task rows

Each experience task row closed with a solid `fa-bolt` glyph. The reference
marks the same slot with the colour `trend-color` sprite followed by "+ N",
and uses that sprite for the 成长体系 heading as well, so the level page also
carried a stray `fa-chart-line` there.

The sprite already ships in the theme (`jiosvg-trend-color`); its path data is
byte-identical to the reference sheet. Both slots now render it, sized to
match the reference (`icon mr6 em09` for the rows, `icon mr6 em12` for the
heading). The "动态" rows keep their wording without a "+", which is how they
read before.

The check-in experience badges in src/Credits/Signin.php stay on
`fa-line-chart` — the reference uses the same monochrome glyph there.

Verification: rendered the real level page through a PHP stub — all ten task
rows emit `#icon-trend-color`, the only Font Awesome glyph left is the
"每日详情" arrow, matching the reference. Screenshotted against the real
stylesheet. A contract test pins both sprite usages and rejects a regression
to `fa-bolt` / `fa-chart-line`; 862 widget/navigation tests pass.

tests/widget-system/user-center-sidebar-icons-contract.test.cjs

@@ -193,3 +193,12 @@ test('余额/积分资产卡的标题图标与参考主题一致', () => {
     assert.doesNotMatch(title, /fa fas fa-money-bill|fa fas fa-coins/, name);
   }
 });
+
+test('等级页经验任务行使用参考主题的 trend-color 图标', () => {
+  const level = read('inc/helpers/user-center-renderers/profile-level.php');
+
+  // 参考主题：每条经验任务 = trend-color + 「+ N」，成长体系标题同图标。
+  assert.match(level, /jio_icon_markup\('jiosvg-trend-color', 'icon mr6 em09'\)/);
+  assert.match(level, /jio_icon_markup\('jiosvg-trend-color', 'icon mr6 em12'\)/);
+  assert.doesNotMatch(level, /fa fas fa-bolt|fa fas fa-chart-line/);
+});